JP4911019B2 - Fluid transmission device - Google Patents

Description

  The present invention relates to a fluid transmission device, and more specifically, a fluid with a lock-up mechanism that can efficiently raise the temperature of hydraulic oil when the hydraulic oil circulating in the fluid transmission mechanism is at a low temperature. The present invention relates to a transmission device.

  Some automatic transmissions use a fluid transmission device provided with a fluid transmission mechanism such as a torque converter in order to smoothly change the operating state such as start and stop. The fluid transmission mechanism transmits a driving force generated by the internal combustion engine to the transmission using hydraulic oil as a medium.

  Some fluid transmission mechanisms, for example, enable lockup in which the driving force of the input shaft is directly transmitted to the output shaft using a transmission means such as a clutch as a medium in a steady operation state. When the lock-up is possible, the driving force is directly transmitted, so that the fuel consumption can be improved more than when the driving force is transmitted to the output shaft using hydraulic oil as a medium. The lock-up is performed by supplying or discharging the hydraulic oil into the fluid transmission mechanism and switching the engagement state of the clutch by the differential pressure of the hydraulic oil between the oil chambers partitioned by the clutch. As a transmission method of driving force by clutch engagement, there are a transmission method by direct clutch engagement and a transmission method by clutch engagement in a slip state. The fluid transmission device disclosed in Patent Document 1 describes a method for performing clutch engagement in a slip state by controlling a differential pressure between two oil chambers in a fluid transmission mechanism as a control method for performing lock-up. Yes.

JP-A-5-99331

  By the way, when the hydraulic oil used for the fluid transmission mechanism is at a low temperature, there is a problem that a clutch friction characteristic that is unstable with respect to the rotation speed is easily caused as compared with a case where the hydraulic oil is at a high temperature. The hydraulic oil filled in the fluid transmission mechanism rises in oil temperature due to frictional heat generated in the fluid transmission mechanism when the driving force is transmitted using the hydraulic oil as a medium. For this reason, in many control methods for fluid transmission devices, control is performed to lock up after the temperature of the hydraulic oil flowing into the fluid transmission mechanism rises to a certain temperature, so that the hydraulic oil is generated in a low temperature state. The above problem was avoided. Therefore, when the hydraulic oil is at a low temperature, the lockup cannot be started until the hydraulic oil rises to a certain temperature. The fluid transmission device shown in Patent Document 2 detects the oil temperature of the hydraulic oil by a valve mechanism using a spring when the hydraulic oil has a low oil temperature, and stops the inflow of the hydraulic oil to the oil cooler that cools the hydraulic oil. In this way, the temperature of the hydraulic oil is increased.

JP-A 64-65558

  However, since the fluid transmission device shown in Patent Document 2 can suppress the inflow to the oil cooler when the hydraulic oil is at a low oil temperature, the heat of the hydraulic oil is released in the circulation path through which the hydraulic oil circulates. The hydraulic oil could not be efficiently heated. Further, in the fluid transmission device disclosed in Patent Document 1, even if the differential pressure in the oil chamber in the fluid transmission mechanism is controlled by the hydraulic control valve, the heat of the hydraulic oil is released in the circulation path, which is efficient. However, the temperature of the hydraulic oil could not be raised.

  The present invention has been made in view of the above, and a fluid transmission device with a lock-up mechanism that can efficiently raise the temperature of hydraulic oil when the hydraulic oil circulating in the fluid transmission mechanism has a low oil temperature. It is about.

  A fluid transmission device according to the present invention has a fluid transmission mechanism that transmits a driving force generated by a driving source using hydraulic oil as a medium, and a clutch engagement side oil chamber partitioned by a clutch in the fluid transmission mechanism and a clutch release. In the fluid transmission device that transmits the driving force without engaging the hydraulic oil by engaging the clutch due to the differential pressure with the side oil chamber, a discharge path for discharging the hydraulic oil supplied to the fluid transmission mechanism, and a discharge path The hydraulic fluid discharged from the clutch is pressurized and supplied to the fluid transmission mechanism, and the hydraulic fluid is supplied to the clutch engagement side oil chamber through communication between the supply route and the clutch engagement side oil chamber. Or a hydraulic control device for releasing the engagement of the clutch by supplying hydraulic oil to the clutch release side oil chamber by communicating the supply path and the clutch release side oil chamber, Fluid transmission mechanism at low oil temperature And interrupting means for interrupting the communication between the discharge path, characterized in that it comprises a.

  According to the present invention, in the fluid transmission device having a circulation path through which hydraulic oil circulates by discharging from the supply and discharge paths to the fluid transmission mechanism, the blocking means for blocking communication between the fluid transmission mechanism and the discharge path is provided. Provided to shut off the hydraulic oil circulation path when the hydraulic oil is at a low oil temperature. Therefore, when the hydraulic oil is at a low oil temperature, a closed circuit that allows the hydraulic fluid circulation path to communicate with the hydraulic control device can be formed without passing the hydraulic oil circulation path through the discharge path. In other words, when the hydraulic oil temperature is low, a closed circuit is formed to shorten the hydraulic oil circulation path, thereby suppressing the release of heat from the hydraulic oil in the circulation path. can do. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device can be improved.

  Further, in the present invention, the hydraulic control device communicates the fluid transmission mechanism and the discharge path when off, and disconnects the fluid transmission mechanism and the discharge path when on, and when the clutch switching valve is on, A hydraulic control valve that controls the hydraulic pressure of the hydraulic oil introduced into the clutch disengagement side oil chamber with respect to the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber, and the clutch switching valve is a shut-off means and operates It is preferable to turn on the clutch switching valve when the oil temperature is low.

  When the fluid transmission mechanism is a torque converter having a diameter, for example, an input-side rotating body connected to an input-side rotating shaft such as a pump impeller, or an output-side rotating body connected to an output-side rotating shaft such as a turbine impeller A rotating body such as is formed. When each rotating body rotates, centrifugal oil pressure generated by centrifugal force is added to the hydraulic oil in the oil chamber in the torque converter adjacent to each rotating body. At this time, the centrifugal oil is applied to the hydraulic oil at the radially outer side of the torque converter, so that the applied centrifugal hydraulic pressure increases. Further, the centrifugal hydraulic pressure added to the hydraulic oil increases according to the rotational speed of the rotating body. Since the rotational speed of the input-side rotating shaft is higher than the rotational speed of the output-side rotating shaft, the rotational speed difference between the rotational speed of the input-side rotating body and the output-side rotating body causes a difference in the clutch engagement-side oil chamber. Between the hydraulic oil (hereinafter simply referred to as “clutch engagement side oil chamber”) and the hydraulic oil in the clutch release side oil chamber (hereinafter simply referred to as “clutch release side oil chamber”). A differential pressure is generated due to the difference between the two. Therefore, a differential pressure is generated between the outside of the clutch engagement side oil chamber and the outside of the clutch release side oil chamber having the same diameter as the outside of the clutch engagement side oil chamber. Since the outside of the clutch engagement side oil chamber and the outside of the clutch release side oil chamber communicate with each other, the hydraulic oil in the torque converter circulates due to the generation of the differential pressure. Thereby, since the hydraulic oil in the circulation path circulates, the heat generated in the torque converter is easily released by the circulation of the hydraulic oil.

  Therefore, when the hydraulic oil temperature is low, turning on the clutch switching valve cuts off the communication between the fluid transmission mechanism and the discharge path, and connects the fluid transmission mechanism and the hydraulic control valve via the clutch switching valve. The closed circuit of hydraulic fluid is formed by making it communicate. Further, the differential pressure generated between the outside of the clutch release side oil chamber and the outside of the clutch engagement side oil chamber is suppressed by adjusting the hydraulic pressure introduced into the clutch release side oil chamber by the hydraulic control valve. be able to. Therefore, by making it difficult for the hydraulic oil to circulate in the circulation path due to the differential pressure, it is possible to suppress the heat generated in the torque converter from being discharged due to the hydraulic oil being discharged by the circulation. The operating oil in the torque converter can be heated. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device can be improved.

Further, in the present invention, the hydraulic control valve subtracts the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber from the hydraulic pressure of the hydraulic oil introduced into the clutch release side oil chamber when the hydraulic oil has a low oil temperature. the control pressure difference is a value when the P _0, it is preferable to control the differential pressure P ₀ is 0 or more.

According to this embodiment, when the hydraulic oil temperature is low, when the hydraulic pressure introduced into the clutch disengagement side oil chamber is controlled by the hydraulic control valve by turning on the clutch switching valve, the control differential pressure P _{0 is set} to 0 or more. And That is, the pressure difference generated between the outside of the clutch disengagement side oil chamber and the outside of the clutch engagement side oil chamber is set to 0 or more in advance due to the difference between the input speed and the output speed. performs control based on the control differential pressure P _0. Therefore, by making it difficult for the hydraulic oil to circulate in the circulation path due to the differential pressure, it is possible to prevent the heat generated in the torque converter from being discharged due to the discharge of the hydraulic oil due to the circulation. In addition, the temperature of the hydraulic oil in the torque converter can be raised. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device can be improved.

In the present invention, the fluid transmission mechanism includes an input-side rotating body to which driving force is transmitted, and an output-side rotating body to which driving force transmitted to the input-side rotating body via hydraulic oil is transmitted. The hydraulic control valve is a torque converter or fluid coupling that increases the difference in rotational speed, which is the value obtained by subtracting the rotational speed of the output-side rotor from the rotational speed of the input-side rotor when the hydraulic oil temperature is low. Along, it is preferable to control to increase the control pressure differential P _0.

According to this aspect, in the case of a rotating body having a diameter such as a torque converter, when the hydraulic pressure is controlled by the hydraulic control valve with the clutch switching valve turned on when the hydraulic oil temperature is low, the input side rotating body The control differential pressure P ₀ is increased as the rotational speed difference, which is a value obtained by subtracting the rotational speed of the output side rotating body from the rotational speed, is increased. That is, when the hydraulic oil temperature is low, the control difference is increased according to the increase in the differential pressure generated between the hydraulic oil in the clutch disengagement side oil chamber and the hydraulic oil in the clutch engagement side oil chamber as the rotational speed difference increases. increasing the pressure _{P 0.} Therefore, by making it difficult for the hydraulic oil to circulate in the circulation path due to the differential pressure, it is possible to prevent the heat generated in the torque converter from being discharged due to the discharge of the hydraulic oil due to the circulation. In addition, the temperature of the hydraulic oil in the torque converter can be raised. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device can be improved.

In the present invention, the fluid transfer device, NI rotational speed of the input side rotating body, the rotational speed of the output rotary member NE, the proportionality constant k and the constant when the k _0, the hydraulic pressure control valve, It is preferable to control the control differential pressure P ₀ based on the following formula (1).
P ₀ = k × (NI × NI−NE × NE) + k ₀ (1)

The increase in hydraulic pressure due to the centrifugal force of each rotating body is proportional to the square of the rotational speed of each rotating body. According to the present invention, when the hydraulic oil temperature is low and the clutch switching valve is turned on and control is performed by the hydraulic control valve, it is proportional to the value obtained by subtracting the square of the output side rotor from the square of the input side rotor. Then, the control differential pressure P ₀ is calculated by the equation (1) obtained by multiplying by the proportional constant k, and the hydraulic control valve is controlled based on the calculated control differential pressure P ₀ . Therefore, by making it difficult for the hydraulic oil to circulate due to the differential pressure generated between the clutch disengagement side oil chamber and the clutch engagement side oil chamber, the heat generated in the torque converter due to the discharge of the hydraulic oil due to the circulation. Can be suppressed, so that the temperature of the hydraulic oil can be increased efficiently. Thereby, since lockup control can be performed at an early stage, the fuel consumption of the fluid transmission device can be improved.

Further, in the present invention, the hydraulic pressure control valve is preferably controlled differential pressure P ₀ and 0.

According to this aspect, when the clutch switching valve is turned on when the hydraulic oil temperature is low, the hydraulic path connected to the clutch disengagement side oil chamber communicates with the hydraulic path introduced to the clutch engagement side oil chamber. As a result, the control differential pressure P ₀ can be controlled to zero. That is, the differential pressure between the hydraulic oil in the clutch release side oil chamber and the hydraulic oil in the clutch engagement side oil chamber is reduced. Therefore, by making it difficult for the hydraulic oil to circulate in the circulation path due to the differential pressure, it is possible to prevent the heat generated in the torque converter from being discharged due to the discharge of the hydraulic oil due to the circulation. In addition, the temperature of the hydraulic oil in the torque converter can be raised. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device can be improved.

  Further, in the present invention, the hydraulic control device communicates the fluid transmission mechanism and the discharge path when off, and disconnects the fluid transmission mechanism and the discharge path when on, and when the clutch switching valve is on, A hydraulic control valve that controls the hydraulic pressure of the hydraulic oil introduced into the clutch disengagement side oil chamber with respect to the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber, and the shut-off means includes a fluid transmission mechanism, a discharge path, The fluid transmission mechanism is provided with urging means for urging the clutch in a direction opposite to the direction in which the clutch is engaged. It is preferable to turn off the communication between the fluid transmission mechanism and the discharge path by the discharge cutoff valve.

  In the present invention, the hydraulic control device communicates the supply path and the clutch engagement side oil chamber when on and engages the clutch, and when off, connects the supply path and clutch release side oil chamber to the clutch. A clutch switching valve for releasing the engagement, and the shut-off means is a discharge shut-off valve that shuts off the communication between the fluid transmission mechanism and the discharge path, and the fluid transmission mechanism is in a direction opposite to the direction in which the clutch is engaged. Preferably, an urging means for urging the clutch is further provided, and the communication between the fluid transmission mechanism and the discharge path is preferably blocked by the discharge cutoff valve when the hydraulic oil temperature is low.

  According to this embodiment, when the hydraulic oil temperature is low, when the clutch switching valve is off, the exhaust cutoff valve is closed, and the circulation path is forcibly cut off when the clutch switching valve is off. A closed circuit can be formed. Accordingly, it is possible to suppress the heat generated in the torque converter from being discharged due to the discharge of the hydraulic oil by circulation, and thus it is possible to efficiently raise the temperature of the hydraulic oil in the torque converter. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device can be improved. Further, when the hydraulic oil circulation path is interrupted, a force is applied to the clutch in the engaging direction due to the differential pressure due to the centrifugal hydraulic pressure generated between the clutch engagement side oil chamber and the clutch release side oil chamber. In this case, by energizing the clutch in a direction opposite to the direction in which the clutch is engaged, engagement of the clutch due to closing of the discharge cutoff valve can be suppressed.

  The fluid transmission device according to the present invention has an effect that the hydraulic oil can be efficiently heated when the hydraulic oil has a low oil temperature.

  Hereinafter, a fluid transmission device according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment 1]
FIG. 1 is a diagram illustrating an entire configuration example (at the time of clutch release) of the fluid transmission device according to the first embodiment. FIG. 2 is a diagram illustrating an example of the overall configuration of the fluid transmission device according to the first embodiment (during clutch engagement). As shown in FIG. 1, the fluid transmission device 1 includes a supply path 2, a torque converter 3, a discharge path 4, and a hydraulic control device OCS. The hydraulic control device OCS according to the first embodiment includes a switching electromagnetic valve 5, a clutch switching valve 6, a hydraulic control solenoid valve 7, and a hydraulic control valve 8. Reference numeral 100 denotes an internal combustion engine as a driving source, and 101 denotes a crankshaft that converts the vertical movement of the piston into a rotational movement and transmits the driving force to the torque converter 3. Reference numeral 102 denotes a transmission shaft for transmitting the driving force transmitted to the torque converter 3 to the transmission 103. 110 is a hydraulic oil temperature sensor, 111 is an input shaft rotational speed sensor, and 112 is an output shaft rotational speed sensor. 120 is a transmission ECU.

  The supply path 2 is a path for supplying pressurized hydraulic oil to the fluid transmission device 1. The supply path 2 includes an oil pan 21, a pressure pump 22, a strainer 23, a first pressure regulating valve 24, a first line oil passage 25, a second pressure regulating valve 26, a second line oil passage 27, It includes a third pressure regulating valve 28, a third line oil passage 29, and piping that communicates with other devices.

  The oil pan 21 is a container for storing hydraulic oil. The oil pan 21 is used in a transmission including the fluid transmission device 1 and stores circulated hydraulic oil. For example, the oil pan 21 stores hydraulic oil discharged from the torque converter 3 via the clutch switching valve 6 and hydraulic oil flowing out from each device including piping in the fluid transmission device 1.

  The pressurizing pump 22 is housed in the oil pan 21 together with the strainer 23. The pressurizing pump 22 sucks and pressurizes the hydraulic oil stored in the oil pan 21 through the strainer 23 that removes impurities, and discharges it to the downstream side. The hydraulic oil pressurized by the pressure pump 22 is connected to the first pressure regulating valve 24, the third pressure regulating valve 28, and the clutch switching via the first line oil passage 25 communicating with the downstream side of the pressure pump 22. It supplies to the reaction pressure oil chamber 6i which the valve 6 mentions later.

First pressure regulating valve 24 is a pressure regulating valve for adjusting the hydraulic pressure or first line pressure Pl ₁ of the first line oil passage 25. The upstream side of the first pressure regulating valve 24 is in communication with the pressurizing pump 22 via the first line oil passage 25. A second line oil passage 27 communicates with the downstream side of the first pressure regulating valve 24. The hydraulic oil discharged downstream from the first pressure regulating valve 24 passes through the second line oil passage 27, the second pressure regulating valve 26, the input port 6d of the clutch switching valve 6 described later, and the hydraulic control valve described later. 8 line pressure ports 8m. The first pressure regulating valve 24 is connected to the transmission ECU 120. The first pressure regulating valve 24 is controlled by the transmission ECU 120 to adjust the first line pressure Pl ₁ . That is, by the transmission ECU 120, the first line pressure Pl ₁ is controlled.

Second pressure regulating valve 26 is a pressure regulating valve for adjusting the hydraulic pressure that is, the second line pressure Pl ₂ of the second line oil passage 27. The upstream side of the second pressure regulating valve 26 is in communication with the first pressure regulating valve 24 via the second line oil passage 27. The downstream side of the second pressure regulating valve 26 communicates with the oil pan 21 via a drain pipe and an orifice. The second pressure regulating valve 26 is connected to the transmission ECU 120. The second pressure regulating valve 26 is controlled by the transmission ECU 120 to adjust the second line pressure Pl ₂ . That is, by the transmission ECU 120, the second line pressure Pl ₂ is controlled.

The third pressure regulating valve 28 is a pressure reducing valve that uses the first line pressure Pl ₁ as a source pressure. The upstream side of the third pressure regulating valve 28 is in communication with the pressurizing pump 22 via the first line oil passage 25. A third line oil passage 29 is communicated with the downstream side of the third pressure regulating valve 28, and the third pressure regulating valve 28 adjusts the oil pressure of the third line oil passage 29, that is, the third line pressure Pl ₃ . The third line pressure Pl ₃ is preset by default. The hydraulic oil adjusted to the third line pressure Pl ₃ by the third pressure regulating valve 28 is supplied to an input port 7d (described later) of the hydraulic control solenoid valve 7.

  The torque converter 3 is a fluid transmission mechanism. The torque converter 3 transmits the driving force generated by the internal combustion engine 100 to the transmission 103 using hydraulic oil as a medium. The hydraulic oil is supplied to the torque converter 3 from the supply path 2. The hydraulic oil supplied to the torque converter 3 is discharged to the discharge path 4. The torque converter 3 is an oil chamber partitioned by a pump impeller 3a, a turbine impeller 3b, a stator impeller 3c, a one-way clutch 3d, a housing 3e, a clutch 3f, a damper 3g, and a clutch 3f. A clutch engagement side oil chamber 3h, a clutch release side oil chamber 3i, and a front cover 3j are included. The stator impeller 3c is interposed between the pump impeller 3a and the turbine impeller 3b, and is attached to the housing 3e, which is a non-rotating member, via the one-way clutch 3d, so that the flow direction of hydraulic oil It is an impeller that guides.

  The pump impeller 3a is an impeller having a plurality of blades rotating in the circumferential direction about the crankshaft 101. The pump impeller 3a is connected to the crankshaft 101 via the front cover 3j. When the crankshaft 101 rotates, the pump impeller 3a rotates integrally with the crankshaft 101. That is, the pump impeller 3a is an input side rotating body to which a driving force is transmitted.

  The turbine impeller 3b is an impeller having a plurality of blades formed so as to face the pump impeller 3a in the axial direction. The turbine impeller 3 b is connected to the transmission 103 via the transmission shaft 102. The driving force from the internal combustion engine 100 transmitted to the pump impeller 3a is transmitted to the turbine impeller 3b using the hydraulic oil flowing into the torque converter 3 as a medium. That is, the turbine impeller 3b is an output-side rotator to which the driving force transmitted to the input-side rotator via the hydraulic oil is transmitted. When the pump impeller 3a rotates, frictional heat is generated between the hydraulic oil and the torque converter 3, and the generated frictional heat is transmitted to the torque converter 3 and the hydraulic oil. Therefore, when the pump impeller 3a rotates, the oil temperature of the hydraulic oil is likely to rise due to the transmission of frictional heat.

The clutch 3f is disposed in the torque converter 3 filled with hydraulic oil. The clutch 3f is connected to the turbine impeller 3b via a damper 3g that absorbs torque fluctuations. Here, the oil chamber formed in the torque converter 3 is divided into a clutch engagement side oil chamber 3h (right side in FIG. 1) and a clutch release side oil chamber 3i (left side in FIG. 1) with the clutch 3f as a boundary. Divided. When the engagement side hydraulic pressure that is the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber 3h is P _3h , and the release side hydraulic pressure that is the hydraulic pressure of the hydraulic oil introduced into the clutch release side oil chamber 3i is P _3i , When the engagement side oil pressure P _3h is higher than the disengagement side oil pressure P _3i , the clutch 3f moves to the clutch disengagement side oil chamber 3i. When the clutch 3f further moves to the clutch release side oil chamber 3i side, the clutch 3f comes into contact with the front cover 3j and engages with the front cover 3j through a half-engaged state. When the clutch 3f and the front cover 3j are engaged, the pump impeller 3a and the turbine impeller 3b are directly connected. Thus, the torque converter 3 having a clutch 3f is due to the pressure difference of the engagement side hydraulic pressure P _3h is a disengagement side pressure P _3i, by engaging the clutch 3f the front cover 3j, the internal combustion engine without passing through the hydraulic oil 100 driving forces can be directly transmitted to the transmission shaft 102. On the other hand, when the engagement side hydraulic pressure P _3h is equal to or less than the release side hydraulic pressure P _3i , the clutch 3f moves toward the clutch engagement side oil chamber 3h, thereby canceling the engagement state with the front cover 3j. be able to.

  The discharge path 4 is a path for discharging the hydraulic oil discharged from the torque converter 3 via the clutch switching valve 6. The discharge path 4 includes an oil cooler 41 and a regulating valve 42.

  The oil cooler 41 is a device for lowering the oil temperature of the hydraulic oil that has risen by circulating in the fluid transmission device 1. The oil cooler 41 is connected to the piping of the discharge path 4, cools the hydraulic oil flowing from the drain port 6 k of the clutch switching valve 6, and discharges it to the oil pan 21, thereby lowering the oil temperature of the flowing hydraulic oil. Is.

  The regulating valve 42 appropriately maintains the pressure of oil flowing from the torque converter 3 to the oil cooler 41 via the discharge path 4. When the oil pressure is high, the oil is discharged toward the oil pan 21 by the adjustment valve 42, and the oil pressure to the oil cooler 41 is prevented from becoming high. The regulating valve 42 is connected to the piping of the discharge path 4 on the upstream side of the oil cooler 41.

The switching solenoid valve 5 is a valve that switches the clutch switching valve 6 on and off by applying a signal pressure generated in an excited state to the clutch switching valve 6. The switching solenoid valve 5 is connected to the transmission ECU 120. When the switching solenoid valve 5 is in a non-excited state (off state), the spherical valve element in the switching solenoid valve 5 is held in a working pressure oil chamber 6a of the clutch switching valve 6 and a switching signal pressure _Psw . The communication with the connected OR valve 51 is blocked. On the other hand, when a signal is received from the transmission ECU 120, the switching solenoid valve 5 is in an excited state (on state), and the switching solenoid solenoid 5a is operated to press the spherical valve element, thereby operating the hydraulic pressure chamber. 6a communicates with the OR valve 51. Thereby, when the switching solenoid valve 5 is in the excited state (on state), the hydraulic pressure in the working pressure oil chamber 6a becomes the switching signal pressure _Psw .

  The clutch switching valve 6 is interposed between the supply path 2 and the torque converter 3, and between the torque converter 3 and the discharge path 4, and is a valve that switches the path of hydraulic fluid that circulates in the fluid transmission device 1 by an on / off operation. It is. That is, the clutch switching valve 6 communicates the torque converter 3 that is a fluid transmission mechanism and the discharge path 4 when off, and blocks communication between the torque converter 3 and the discharge path 4 when on. The clutch switching valve 6 includes an oil passage formed in a member constituting a hydraulic circuit (not shown), a plurality of ports communicating with the oil passage, and a shaft disposed in the oil passage.

The clutch switching valve 6 includes an operating pressure oil chamber 6a, a spool valve element 6b, a drain receiving port 6c, an input port 6d, a switching valve communication port 6e, a spring 6f, a plunger 6g, and a release side port 6h. , The counter working pressure oil chamber 6i, the engagement side port 6j, the drain port 6k, and the R range pressure oil chamber 6l. Here, when the clutch switching valve 6 is turned on, that is, when the operating pressure oil chamber 6a receives the switching signal pressure P _sw from the switching electromagnetic valve 5, the side on which the spool valve element 6b moves is turned on. In this state, the clutch switching valve 6 is turned off, that is, the operating pressure oil chamber 6a is not receiving the switching signal pressure _Psw from the switching electromagnetic valve 5, and the side opposite to the on side is turned off. Let it be the side. Of both ends of the clutch switching valve 6, an end formed on the on side is a clutch switching valve on side closed end, and an end formed on the off side is a clutch switching valve off side closed end.

The working pressure oil chamber 6a is an oil chamber in which an oil passage is sealed by a clutch switching valve off side closed end portion and a spool valve element off side end portion to be described later. The working pressure oil chamber 6a is communicated with the switching solenoid valve 5 by piping. On the other hand, the counteracting pressure oil chamber 6i is an oil chamber in which an oil passage is sealed by a clutch switching valve on side closed end and a spool valve on side end described later. The counter-acting pressure oil chamber 6 i communicates with the first line oil passage 25 and is adjusted to the first line pressure Pl ₁ by the first pressure regulating valve 24 regardless of whether the clutch switching valve 6 is on or off. In switching the solenoid valve 5 is de-energized (off state), hydraulic oil chamber 6a is that the are maintained at drain pressure, anti-working oil chamber 6i is holding the first line pressure Pl ₁ I'm leaning. On the other hand, when the switching solenoid valve 5 is in an excited state (on state), the switching valve pressure 6 _sw acts on the operating pressure oil chamber 6 a from the switching solenoid valve 5, whereby the spool valve element 6 b moves to the on side. .

  The spool valve element 6 b is a shaft that switches the connection state of each port provided in the clutch switching valve 6. The spool valve element 6b has both ends having diameters that allow the adjacent oil chambers to be sealed, that is, an end part on the spool valve element on the off side and an end part on the on side. and an on-side end. The end portion on the spool valve element off side is formed in a structure (for example, a protruding shape) in which the working pressure oil chamber 6a is formed even if the end portion on the off side of the clutch switching valve 6 abuts. The end portion on the spool valve element on side is formed in a structure (for example, a protruding shape) in which the control signal pressure oil chamber 8l is formed even if it abuts on a plunger off side end portion of a plunger 6g described later. The end portion on the spool valve element on side is connected to a spring 6f that biases the spool valve element 6b to the off side. The spool valve element 6b has a diameter that enables sealing in addition to both ends, and switches the connection state of each port by movement.

The clutch switching valve 6 is off state, the spool 6b, the force acting to the off side of the first line pressure Pl ₁ to spool on end, with which is biased off side by the spring 6f Force F _sp6 acts. Therefore, the spool valve element 6b moves to the off side, and the spool valve element off-side end part comes into contact with the off-side end part of the clutch switching valve 6 so that the spool valve element 6b is positioned on the off side.

On the other hand, when the clutch switching valve 6 is in the on state, the switching signal pressure P _sw acts on the hydraulic pressure oil chamber 6a from the switching electromagnetic valve 5 that has received the on signal from the transmission ECU 120. Therefore, the spool valve element 6b has a force acting on the spool valve element off-side end portion by the switching signal pressure P _sw and the first line pressure Pl ₁ to the spool valve element on-side end portion to the off side. The acting force and the biasing force _Fsp6 to the off side due to the contraction of the spring 6f connected to the end portion on the spool valve element on side act. Off this time, the switching signal pressure _{P sw} is the switching signal pressure _{P sw} force acting on the on side spool off side end, the first line pressure Pl ₁ to spool on end It is set in advance to be larger than the sum of the force acting on the side and the biasing force _Fsp6 acting on the off side by the spring 6f. That is, when the switching signal pressure _Psw acts on the spool valve element 6b, the force acting on the on side becomes stronger than the force acting on the off side. Therefore, the spool valve element 6b moves to the on side, and the plunger off side end of the plunger 6g described later is in contact with the on side closed end of the clutch switching valve 6 so that the spool valve element 6b is positioned on the on side. Become.

  The drain receiving port 6 c communicates with a drain pipe that communicates with the second pressure regulating valve 26. As shown in FIG. 1, the drain receiving port 6 c is blocked by the spool valve element 6 b in the clutch switching valve 6 when the clutch switching valve 6 is off. On the other hand, the drain receiving port 6c communicates with the drain port 6k as shown in FIG. 2 when the clutch switching valve 6 is on.

The input port 6d is introduced with hydraulic oil having the second line pressure Pl ₂ adjusted by the second pressure regulating valve 26. The input port 6d communicates with the disengagement side port 6h as shown in FIG. 1 when the clutch switching valve 6 is turned off. On the other hand, when the clutch switching valve 6 is on, the input port 6d communicates with the engagement side port 6j as shown in FIG.

  The switching valve communication port 6e is connected to a later-described second line pressure port 8n of the hydraulic control valve 8 by piping. As shown in FIG. 1, the switching valve communication port 6e is blocked by the spool valve element 6b when the clutch switching valve 6 is off. On the other hand, the switching valve communication port 6e communicates with the disengagement side port 6h as shown in FIG. 2 when the clutch switching valve 6 is on.

  The plunger 6g is provided on the on side of the spool valve element 6b and is a shaft that constitutes the inside of the clutch switching valve 6 together with the spool valve element 6b. The plunger 6g has both ends having diameters that allow the adjacent oil chambers to be sealed, that is, the plunger valve off side end that is the end on the off side, and the plunger valve element on the side that is the end on the side. And an end portion. Even if the plunger off-side end is in contact with the spool valve element on-side end, an oil chamber is formed in which the plunger off-side end and the spool valve element on-side end are formed (for example, projecting) It is formed with. The plunger on-side end portion is formed in a structure (for example, a protrusion shape) in which a counter-acting pressure oil chamber 6i is formed even if it contacts the on-side closed end portion of the clutch switching valve 6.

The release side port 6h communicates with the clutch release side oil chamber 3i by piping. Release side port 6h is sometimes clutch switching valve 6 is off, as shown in FIG. 1, communicates with the input port 6d of the second line pressure Pl ₂ acts adjusted by the second adjusting valve 26. Accordingly, the second line pressure Pl _2, the clutch switching valve 6 is at off, through the release side port 6h communicating with the clutch release side oil chamber 3i, is introduced into clutch release side oil chamber 3i.

The engagement side port 6j is communicated with the clutch engagement side oil chamber 3h by piping. As shown in FIG. 1, the engagement side port 6j communicates with the drain port 6k when the clutch switching valve 6 is turned off. That is, when the clutch switching valve 6 is turned off, the torque converter 3 and the discharge path 4 communicate with each other. On the other hand, the engagement-side port 6j is sometimes on the clutch switching valve 6, as shown in FIG. 2, it communicates with the input port 6d of the second line pressure Pl ₂ acts adjusted by the second adjusting valve 26. Accordingly, the second line pressure Pl ₂ is sometimes on the clutch switching valve 6, via the engagement-side port 6j which is connected to the clutch disengagement side oil chamber 3i, is introduced into the clutch engagement side oil chamber 3h.

  The drain port 6k communicates with the discharge path 4 by piping. As shown in FIG. 1, the drain port 6k communicates with the engagement side port 6j when the clutch switching valve 6 is turned off. As a result, the hydraulic oil that has flowed in from the clutch engagement side oil chamber 3 h is introduced into the discharge path 4. On the other hand, when the clutch switching valve 6 is turned on, the drain port 6k is disconnected from the drain port 6k communicating with the torque converter 3 by piping as shown in FIG. Therefore, the clutch switching valve 6 serves as a shut-off means for shutting off the hydraulic oil introduced from the clutch engagement side oil chamber 3h to the discharge path 4 by turning on the clutch switching valve 6. The drain port 6k communicates with the drain receiving port 6c when the clutch switching valve 6 is on. As a result, the hydraulic oil that has flowed out of the second pressure regulating valve 26 is introduced into the discharge path 4.

  The R range pressure oil chamber 6l is an oil chamber provided for applying an R range pressure between the spool valve element on side closed end and the plunger off side closed end. The manual valve 61 generates an R range pressure when a shift operation lever (not shown) is in the R range.

The hydraulic control solenoid valve 7 is a pressure reducing valve that uses the third line pressure Pl ₃ regulated by the third pressure regulating valve 28 as a source pressure. The hydraulic control solenoid valve 7 is a valve for generating a control signal pressure P _lin that acts on the control signal pressure oil chamber 8 l of the hydraulic control valve 8. In the longitudinal direction of the hydraulic control solenoid valve 7, a plurality of ports serving as hydraulic oil inlets and outlets are provided. The hydraulic control solenoid valve 7 includes a control electromagnetic solenoid 7a, a spool valve element 7b, a spring 7c, an input port 7d, an output port 7e, and a solenoid oil chamber 7f.

The hydraulic control solenoid valve 7 includes an oil passage formed in a member constituting a hydraulic circuit (not shown), a plurality of ports communicating with the oil passage, and a shaft disposed in the oil passage. A control electromagnetic solenoid 7a is formed at one end of the hydraulic control solenoid valve 7, and a spool valve element 7b is disposed in the oil passage. The spool valve element 7b is connected to a spring 7c formed on the side opposite to the control electromagnetic solenoid 7a. The control electromagnetic solenoid 7a is connected to the transmission ECU 120. The control electromagnetic solenoid 7a receives the drive current I _sol from the transmission ECU 120, and acts on the spool valve element 7b according to the drive current I _sol to move to the spring 7c side.

  The spool valve element 7 b is a shaft that adjusts the connection state of each port provided in the hydraulic control solenoid valve 7. The spool valve element 7b is urged to the opposite side to the spring 7c by a connected spring 7c. The spool valve element 7b has a cutoff control shaft 7bz that adjusts an opening through which the input port 7d and the solenoid oil chamber 7f communicate.

The input port 7 d is in communication with the third line oil passage 29. A third line pressure Pl ₃ adjusted by the third pressure regulating valve 28 is introduced to the input port 7d. The input port 7d communicates with the solenoid oil chamber 7f by having an opening with the solenoid oil chamber 7f when the hydraulic control solenoid valve 7 does not receive a signal from the transmission ECU 120. At this time, the solenoid oil chamber 7f communicates with the output port 7e, so that the input port 7d communicates with the output port 7e. The output port 7e communicates with a control signal pressure oil chamber 8l of a hydraulic control valve 8 described later via a pipe.

Here, the operation in which the hydraulic control solenoid valve 7 applies the control signal pressure P _lin to the control signal pressure oil chamber 8 l of the hydraulic control valve 8 will be described. When the drive current I _sol from the transmission ECU 120 is supplied to the control electromagnetic solenoid 7a, the control electromagnetic solenoid 7a acts on the spool valve element 7b according to the drive current I _sol to move to the spring 7c side. . When the spool valve element 7b moves toward the spring 7c against the urging force, the opening of the input port 7d and the solenoid oil chamber 7f is gradually blocked by the blocking control shaft 7bz. When opening the input port 7d and the solenoid oil chamber 7f it is gradually blocked by cutoff control shaft 7Bz, by the hydraulic pressure in the third line pressure Pl ₃ by elevated solenoid oil chamber 7f is gradually decreased, the output port The control signal pressure P _lin acting on the control signal pressure oil chamber 8l from 7e also gradually decreases. Therefore, when the opening between the input port 7d and the solenoid oil chamber 7f is maximum, the control signal pressure P _lin becomes maximum (P _{lin (MAX)} ), and the opening between the input port 7d and the solenoid oil chamber 7f is cut off. In this case, the control signal pressure P _lin becomes the minimum (P _{lin (MIN)} ). Therefore, by controlling the drive current I _sol from the transmission ECU 120, the hydraulic control solenoid valve 7 can control the control signal pressure P _{lin in} the range of P _{lin (MAX)} to P _{lin (MIN).} .

The hydraulic control valve 8 is a valve that controls the hydraulic pressure of the clutch disengagement side oil chamber 3 i in the torque converter 3 through the clutch switching valve 6 by the control signal pressure P _lin received from the hydraulic control solenoid valve 7. The hydraulic control valve 8 includes a communication side oil chamber 8a, a hydraulic control side oil chamber 8b, a plunger 8c, a first land 8d, a second land 8e, a spool valve element 8f, a third land 8g, 4 land 8h, 5th land 8i, hydraulic control oil chamber 8j, spring 8k, control signal pressure oil chamber 8l, line pressure port 8m, second line pressure port 8n, drain port 8p, It is comprised including. The hydraulic control valve 8 includes an oil passage formed in a member constituting a hydraulic circuit (not shown), a plurality of ports communicating with the oil passage, and a shaft disposed in the oil passage. Here, the side on which the spool valve element 8f moves together with the increase in the control signal pressure P _lin is defined as the hydraulic control side, and the opposite side is defined as the communication side. Of both ends of the hydraulic control valve 8, an end formed on the hydraulic control side is a hydraulic control side closed end, and an end formed on the communication side is a communication side closed end.

The communication side oil chamber 8a is an oil chamber whose oil path is sealed by the communication side closed end of the hydraulic control valve 8 and the first land 8d. The communication side oil chamber 8a communicates with the disengagement side port 6h of the clutch switching valve 6 through the piping, so that the disengagement side oil pressure _P3i acts. On the other hand, the hydraulic control side oil chamber 8b is an oil chamber whose oil path is sealed by the hydraulic control side closed end portion of the hydraulic control valve 8 and the second land 8e. The oil pressure control side oil chamber 8b communicates with the disengagement side port 6h of the clutch switching valve 6 through a pipe, so that the engagement side oil pressure _P3h acts.

The plunger 8 c is a shaft that is disposed in the oil passage of the hydraulic control valve 8. The plunger 8c is arranged on the communication side of the spool valve element 8f. The plunger 8c has a land formed by dividing an oil passage of the hydraulic control valve 8. Plunger 8c has a first land 8d having a cross-sectional area _{A 1,} a second land 8e having a cross-sectional area _{A 2} are formed.

  The first land 8d is formed at the communication side end of the plunger 8c. Even if the first land 8d is in contact with the communication side end of the hydraulic control valve 8, a structure (for example, a projection) in which the communication side oil chamber 8a is formed is formed on the communication side.

  The second land 8e is formed at the hydraulic control side end of the plunger 8c. Even if the second land 8e is in contact with the third land 8g which is the end of the spool valve element 8f on the communication side, a structure (for example, a protrusion) in which the control signal pressure oil chamber 8l is formed is formed on the hydraulic control side. ing.

The spool valve element 8 f is a shaft disposed in the oil passage of the hydraulic control valve 8. The spool valve element 8f is disposed on the hydraulic pressure control side of the plunger 8c. The spool valve element 8 f is formed with a land that can divide the oil passage of the hydraulic control valve 8. Spool 8f includes a third land 8g having a cross-sectional area _{A 3,} and the fourth land 8h having the cross-sectional area _{A 4,} and a fifth land 8i spring 8k are connected, are formed.

  The third land 8g is formed at the communication side end of the spool valve element 8f. Even if the third land 8g contacts the second land 8e which is the end of the hydraulic pressure control on the plunger 8c, a structure (for example, a protrusion) in which the control signal pressure oil chamber 8l is formed is formed on the hydraulic control side. Yes.

  The fourth land 8h is formed between the third land 8g and the fifth land 8i. The fourth land 8h blocks the line pressure port 8m when the spool valve element 8f moves to the hydraulic pressure control side.

The fifth land 8i is formed at the hydraulic control side end of the spool valve element 8f. The spring 8k is arranged in a state where the fifth land 8i is biased. Even if the fifth land 8i is in contact with the closed end of the hydraulic control side, a structure (for example, a protrusion) in which the hydraulic control side oil chamber 8b is formed is formed on the hydraulic control side. In addition, the cross-sectional area of each land formed in the plunger 8c and the spool valve element 8f has a relationship of A ₃ > A ₁ (= A ₄ )> A ₂ .

  The hydraulic control oil chamber 8j is an oil chamber whose oil path is sealed by the fourth land 8h and the fifth land 8i. The hydraulic control oil chamber 8j communicates with the second line pressure port 8n regardless of the movement of the spool valve element 8f. When the spool valve element 8f moves to the hydraulic pressure control side, the hydraulic control oil chamber 8j is blocked from communication with the line pressure port 8m by being blocked by the fourth land 8h. When the hydraulic control oil chamber 8j moves to the communication side of the spool valve element 8f, the communication with the drain port 8p is blocked due to the blockage by the fifth land 8i.

The control signal pressure oil chamber 8l is an oil chamber communicated with the output port 7e of the hydraulic control solenoid valve 7 through a pipe. Therefore, the control signal pressure oil chamber 8l is operated by the control signal pressure P _{lin in} the range from the hydraulic control solenoid valve 7 to P _{lin (MAX)} to P _{lin (MIN)} .

The line pressure port 8 m communicates with the second line oil passage 27. The hydraulic fluid having the second line pressure Pl ₂ adjusted by the second pressure regulating valve 26 is introduced into the line pressure port 8m. As shown in FIG. 1, when the maximum value P _{lin (MAX)} of the control signal pressure P _lin acts on the control signal pressure oil chamber 8l, the spool valve element 8f moves to the hydraulic pressure control side. At this time, the line pressure port 8m is disconnected from the hydraulic control oil chamber 8j by the fourth land 8h. As shown in FIG. 2, when the control signal pressure P _lin is applied to the control signal pressure oil chamber 8l and the hydraulic pressure in the clutch release side oil chamber 3i is controlled, the spool valve element 8f is hydraulically controlled. Move to the control side. At this time, the line pressure port 8m is disconnected from the hydraulic control oil chamber 8j by the fourth land 8h.

The second line pressure port 8n is communicated with the switching valve communication port 6e via a pipe. When the clutch switching valve 6 is off, the second line pressure port 8n has a switching valve communication port 6e that is blocked by the spool valve element 6b as shown in FIG. It becomes a drain port for draining hydraulic oil. When the clutch switching valve 6 is on, the second line pressure port 8n communicates with the switching valve communication port 6e communicated with the release side port 6h via the piping as shown in FIG. Hydraulic pressure P _3i is introduced.

  The drain port 8p is a discharge port for discharging the hydraulic oil in the hollow portion of the hydraulic control valve 8. The hydraulic oil discharged from the drain port 8p is discharged to the oil pan 21.

Here, the operation of the hydraulic control valve 8 will be described. First, when the control signal pressure P _{lin (MAX)} is added to the control signal pressure oil chamber 8l of the hydraulic control valve 8, as shown in FIG. 1, the control signal pressure P _lin via the third land 8g. _The spool valve element 8f moves to the hydraulic control side by the force acting on the hydraulic control side from _{lin (MAX),} contacts the hydraulic control side closed end of the hydraulic control valve 8, and moves to the hydraulic control side. It is in a stopped state, that is, a state fixed at the hydraulic control side position. At this time, the line pressure port 8m and the hydraulic control oil chamber 8j are blocked by the fourth land 8h, and the second line pressure port 8n and the drain port 8p are in communication with each other. The plunger 8c is also moved to the hydraulic control side by the force acting from the release side hydraulic pressure _P3i to the hydraulic pressure control side via the first land 8d and comes into contact with the spool valve element 8f.

Further, when the hydraulic pressure of the clutch release side oil chamber 3i is controlled, as shown in FIG. 2, it acts on the control signal pressure oil chamber 8l of the hydraulic control valve 8 in accordance with the drive current I _sol from the transmission ECU 120. Since the control signal pressure P _lin to be gradually decreased from P _{lin (MAX)} , the spool valve element 8f gradually moves from the state fixed at the hydraulic control side position to the communication side. At this time, when the clutch switching valve 6 is on, that is, when hydraulic fluid is introduced into the second line pressure port 8n, the opening formed by the communication between the second line pressure port 8n and the drain port 8p is blocked. By performing this control, the flow rate of the hydraulic oil discharged to the oil pan 21 through the drain port 8p can be controlled. Therefore, by controlling the control signal pressure P _lin acting on the control signal pressure oil chamber 8l, the flow rate of the hydraulic oil discharged to the oil pan 21 through the drain port 8p is controlled, so that the release side The hydraulic pressure P _3i can be controlled. The plunger 8c contacts the spool valve element 8f that moves to the communication side and moves to the communication side.

When the minimum value P _{lin (MIN) of} the control signal pressure P _lin acts on the hydraulic control valve 8, the control signal pressure P _lin acting on the control signal pressure oil chamber 8 l of the hydraulic control valve 8 is further increased. Therefore, the spool valve element 8f moves to the communication side and comes into contact with the plunger 8c. When the plunger 8c comes into contact with the communication side closed end of the hydraulic control valve 8, the movement to the communication side is stopped. In other words, the state is fixed at the hydraulic control side position. At this time, the fourth land 8h that has blocked communication between the line pressure port 8m and the hydraulic control oil chamber 8j moves to the communication side, so that communication between the line pressure port 8m and the hydraulic control oil chamber 8j is blocked. , Released. On the other hand, since the fifth land 8i moves to the communication side, the communication between the drain port 8p and the hydraulic control oil chamber 8j is cut off, so that the hydraulic oil is not discharged from the hydraulic control valve 8.

  The hydraulic oil temperature sensor 110 is an oil temperature measuring unit that detects the oil temperature of the hydraulic oil. The hydraulic oil temperature sensor 110 is connected to the transmission ECU 120 and outputs the temperature of the hydraulic oil every unit time to the transmission ECU 120. In the first embodiment, the hydraulic oil temperature sensor 110 is disposed in a pipe that connects the clutch engagement side oil chamber 3h and the engagement side port 6j, which are in the vicinity of the torque converter 3. That is, the hydraulic oil temperature sensor 110 is provided in the vicinity of the torque converter 3, and the hydraulic oil temperature measured by the hydraulic oil temperature sensor 110 is output to the transmission ECU 120, whereby the hydraulic oil temperature in the torque converter 3 is reduced. I can grasp it.

  The input shaft rotational speed sensor 111 is a rotational speed sensor that detects the rotational speed of the crankshaft 101 that is an input side rotating body to which a driving force is transmitted. The input shaft rotational speed sensor 111 is connected to the transmission ECU 120. When the crankshaft 101 rotates, the input shaft rotational speed sensor 111 detects an input rotational speed NI that is the rotational speed of the crankshaft 101 and outputs a signal of the input rotational speed NI to the transmission ECU 120.

  The output shaft rotational speed sensor 112 is a rotational speed sensor that detects the rotational speed of the transmission shaft 102 that is an output side rotational body to which the driving force transmitted to the input side rotational body is transmitted through the hydraulic oil. The output shaft speed sensor 112 is connected to the transmission ECU 120. When the transmission shaft 102 rotates, the output shaft rotational speed sensor 112 detects an output rotational speed NE that is the rotational speed of the transmission shaft 102 and outputs a signal of the output rotational speed NE to the transmission ECU 120.

  The transmission ECU 120 is an electronic control device, and is a so-called microcomputer including a CPU, a ROM, a RAM, an interface, and the like (not shown). The transmission ECU 120, for example, the oil temperature of the hydraulic oil detected by the hydraulic oil temperature sensor 110, the input shaft rotational speed that is the rotational speed of the crankshaft 101, the output shaft rotational speed that is the rotational speed of the transmission shaft 102, Is input as a signal. The CPU of the transmission ECU 120 processes the input signal based on the input signal and a program stored in the ROM in advance using the temporary storage function of the RAM. In order to execute the engagement control of the clutch 3f and the switching of the hydraulic oil circulation path when the torque converter 3 is at a low oil temperature, the first pressure regulating valve 24, the second pressure regulating valve 26, the clutch switching valve 6 and the hydraulic control solenoid valve 7 is controlled.

Here, the circulation of the hydraulic oil in the fluid transmission device 1 when the clutch 3f shown in FIG. 1 is released will be described. In the fluid transmission device 1 shown in FIG. 1, when the clutch switching valve 6 is turned off, the clutch 3f is released from the engagement (released state). In case the clutch switching valve 6 is off, by a release side port 6h and the input port 6d of the clutch switching valve 6 is communicated, the second line of the pressure Pl ₂ hydraulic oil adjusted by the second pressure regulating valve 26 is torque It is introduced into the clutch release side oil chamber 3 i of the converter 3. In addition, the engagement side port 6j and the drain port 6k of the clutch switching valve 6 communicate with each other, so that the hydraulic oil in the clutch engagement side oil chamber 3h flows into the discharge path 4 without being interrupted in the middle path. Discharged. The hydraulic oil that has flowed into the discharge path 4 is cooled by the oil cooler 41 in the discharge path 4, and is discharged to the oil pan 21 through the adjustment valve 42. The hydraulic oil discharged to the oil pan 21 is circulated in the fluid transmission device 1 by being supplied to the fluid transmission device 1 through the supply path 2 again.

Next, the hydraulic oil circulation path in the fluid transmission device 1 when the clutch 3f shown in FIG. 2 is engaged will be described. In the fluid transmission device 1 shown in FIG. 2, when the clutch switching valve 6 is turned on, the clutch 3f is engaged. When the clutch switching valve 6 is on, the input port 6d of the clutch switching valve 6 and the engagement side port 6j communicate with each other, so that the hydraulic oil having the second line pressure Pl ₂ adjusted by the second pressure regulating valve 26 is obtained. Is introduced into the clutch engagement side oil chamber 3h. Further, since the release side port 6h and the switching valve communication port 6e communicate with each other, the hydraulic oil in the clutch release side oil chamber 3i is supplied to the second line pressure port of the hydraulic control valve 8 communicated with the switching valve communication port 6e through a pipe. Flows into 8n. At this time, when the control signal pressure P _lin acts on the hydraulic control oil chamber 8j, the hydraulic oil flowing into the second line pressure port 8n is adjusted in flow rate by the fifth land 8i and discharged to the oil pan 21. And the release side hydraulic pressure P _3i is controlled. The hydraulic oil discharged to the oil pan 21 is circulated in the fluid transmission device 1 by being supplied to the fluid transmission device 1 through the supply path 2 again.

In the fluid transmission device 1 shown in the first embodiment, the clutch 3f is engaged and the clutch 3f and the front cover 3j are completely engaged, and the clutch 3f and the front cover 3j. And a semi-engaged state in which sliding friction is generated between them. That is, the release side hydraulic pressure P _3i is adjusted by controlling the control signal pressure P _lin acting on the control signal pressure oil chamber 8 l of the hydraulic control valve 8. The engagement state of the clutch 3f can be adjusted by adjusting the release side hydraulic pressure _P3i . The transmission ECU 120 calculates a rotational speed difference that is a difference between the rotational speed of the crankshaft 101 and the rotational speed of the transmission shaft 102, and controls the control signal pressure P _{lin based} on the calculated rotational speed difference. Thereby, the engagement state of the clutch 3f can be adjusted by controlling the disengagement side hydraulic pressure _P3i in accordance with the rotational speed difference. Therefore, in the hydraulic oil circulation path in the fluid transmission device 1 shown in FIG. 2, the clutch 3f is in a fully engaged state, but is released through a half-engaged state by reducing the disengagement side hydraulic pressure P _3i. It can be.

  Next, a control method for the fluid transmission device according to the first embodiment will be described. FIG. 3 is a diagram illustrating a flow of the control method of the fluid transmission device according to the first embodiment. FIG. 4 is a diagram illustrating an example of the overall configuration of the fluid transmission device according to the first embodiment.

  As shown in FIG. 3, first, the transmission ECU 120 acquires the oil temperature T of the hydraulic oil output from the hydraulic oil temperature sensor 110 (step ST11). That is, the oil temperature T of the hydraulic oil is the oil temperature of the hydraulic oil in the pipe communicating the clutch engagement side oil chamber 3h and the engagement side port 6j in the vicinity of the torque converter 3.

  Next, the transmission ECU 120 determines whether or not the oil temperature T of the hydraulic oil is equal to or lower than the specified oil temperature T1 (step ST12). Here, the specified oil temperature T1 is a numerical value set in advance, and is a temperature at which unstable clutch friction characteristics are caused when performing lock-up. Thereby, it is determined that the hydraulic oil circulating in the torque converter 3 has a low oil temperature.

  Next, when the transmission ECU 120 determines that the hydraulic oil temperature T is equal to or lower than the specified oil temperature T1 (Yes in step ST12), the transmission ECU 120 outputs a lockup prohibition flag (step ST13). In addition, transmission ECU120 will output a lockup permission flag, if it judges that the oil temperature T of the received hydraulic fluid is not below regulation oil temperature T1 (step ST12 negative) (step ST16). As a result, lock-up is permitted and the process proceeds to the next control cycle.

Next, the transmission ECU 120 outputs a signal to the switching electromagnetic valve 5 so that the clutch switching valve 6 is turned on (step ST14). That is, the switching solenoid valve 5 that has received a signal from the transmission ECU 120 applies the switching signal pressure P _sw to the operating pressure oil chamber 6 a of the clutch switching valve 6, so that the clutch switching valve 6 is turned on. That is, as shown in FIG. 4, when the input port 6d of the clutch switching valve 6 and the engagement side port 6j communicate with each other, the hydraulic fluid of the second line pressure Pl ₂ adjusted by the second pressure regulating valve 26 is transferred to the clutch. It is introduced into the engagement side oil chamber 3h. Further, since the release side port 6h and the switching valve communication port 6e communicate with each other, the hydraulic oil in the clutch release side oil chamber 3i is supplied to the second line pressure port of the hydraulic control valve 8 communicated with the switching valve communication port 6e through a pipe. Flows into 8n.

Next, as shown in FIG. 3, the transmission ECU 120 sets the control signal pressure P _lin acting on the control signal pressure oil chamber 8 l of the hydraulic control valve 8 to P _{lin (MIN)} . Here, the transmission ECU 120 outputs a signal to the hydraulic control solenoid valve 7 so that the control signal pressure P _lin becomes P _{lin (MIN)} (step ST15). Thereby, as shown in FIG. 4, the control signal pressure P _lin acting on the control signal pressure oil chamber 8l of the hydraulic control valve 8 becomes P _{lin (MIN)} . Accordingly, the spool valve element 8f of the hydraulic control valve 8 moves to the communication side, and the communication between the hydraulic control oil chamber 8j and the drain port 8p is blocked by the fifth land 8i. That is, hydraulic oil is not discharged from the hydraulic control valve 8. Therefore, by executing the control method according to the first embodiment, when the hydraulic oil is at a low oil temperature, the hydraulic oil is not transferred between the torque converter 3, the clutch switching valve 6, and the hydraulic control valve 8 without passing through the discharge path 4. A closed circuit can be formed. Therefore, by performing the control according to the first embodiment, the hydraulic oil circulation path can be shortened as compared with the case where the hydraulic oil is circulated through the discharge path 4 when the hydraulic oil has a low oil temperature. That is, it is possible to suppress release of heat from the hydraulic oil in the circulation path. In addition, by performing the control according to the first embodiment, the hydraulic oil can be circulated by the oil cooler 41 that lowers the oil temperature and the circulation path that avoids the inflow to the oil pan 21 that contacts the air. Therefore, the release of heat from the hydraulic oil in the circulation path can be suppressed. As a result, the operating oil in the torque converter 3 can be efficiently heated. When the transmission ECU 120 outputs a signal to the hydraulic control solenoid valve 7 so that the control signal pressure P _lin acting on the control signal pressure oil chamber 8 l of the hydraulic control valve 8 becomes P _{lin (MIN)} , Transition to the control cycle.

Here, as shown in FIG. 4, by setting the control signal pressure P _lin acting on the control signal pressure oil chamber 8l of the hydraulic control valve 8 to P _{lin (MIN)} , the line pressure port by the fourth land 8h. The disconnection of communication between 8m and the hydraulic control oil chamber 8j is released. Accordingly, the line pressure port 8m communicating with the clutch engagement side oil chamber 3h and the second line pressure port 8n communicating with the clutch release side oil chamber 3i communicate with each other, and the engagement side hydraulic pressure _P3h and the release side hydraulic pressure are communicated. P _3i has the same pressure. That is, when the control differential pressure that is a value obtained by subtracting the engagement side hydraulic pressure P _3h from the release side hydraulic pressure P _3i is set to P ₀ , the transmission ECU 120 performs control to set the control differential pressure P ₀ to zero. Therefore, by reducing the differential pressure between the release side hydraulic pressure P _3i and the engagement side hydraulic pressure P _3h, it is difficult to circulate the hydraulic oil in the circulation path. In other words, by making it difficult for the hydraulic oil to circulate in the circulation path, it is possible to prevent the heat generated in the torque converter 3 from being discharged due to the discharge of the hydraulic oil by the circulation. The operating oil in the converter 3 can be heated. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device 1 can be improved.

[Embodiment 2]
Next, the fluid transmission device 1 according to the second embodiment will be described. FIG. 5 is a diagram illustrating an overall configuration example of the fluid transmission device according to the second embodiment. FIG. 6 is a diagram illustrating a flow of the control method of the fluid transmission device according to the second embodiment.

The difference between the first embodiment and the second embodiment is a method for controlling the hydraulic control valve 8 by the transmission ECU 120. In the first embodiment, the control differential pressure P _{0 is set} to P ₀ = 0 as shown in FIG. relative to control, the second embodiment, as shown in FIG. 6, calculates a control differential pressure P ₀ on the basis of the input rotational speed NI and the output rotational speed NE, the calculated control differential pressure P ₀ It is a point to control based on. Since the basic configuration of the first embodiment and the second embodiment is the same, the description will be omitted or simplified. Regarding the control method of the second embodiment, the above differences will be described below, and common points will be omitted or simplified.

  First, as shown in FIG. 6, the transmission ECU 120 acquires the oil temperature T of the hydraulic oil from the hydraulic oil temperature sensor 110 (step ST21).

  Next, the transmission ECU 120 acquires the input rotational speed NI output from the input shaft rotational speed sensor 111 and the output rotational speed NE output from the output shaft rotational speed sensor 112 (step ST22).

  Next, the transmission ECU 120 determines whether or not the oil temperature T of the hydraulic oil is equal to or lower than the specified oil temperature T1 (step ST23). Thereby, it is determined whether or not the hydraulic oil circulating in the torque converter 3 has a low oil temperature.

  Next, when the transmission ECU 120 determines that the hydraulic oil temperature T is equal to or lower than the specified oil temperature T1 (Yes in step ST23), the transmission ECU 120 outputs a lockup prohibition flag (step ST24). Note that when the transmission ECU 120 determines that the hydraulic oil temperature T is not equal to or lower than the specified oil temperature T1 (No in step ST23), the transmission ECU 120 outputs a lockup permission flag (step ST28). As a result, lock-up is permitted and the process proceeds to the next control cycle.

Next, the transmission ECU 120 calculates the control differential pressure P ₀ from the input rotational speed NI, the output rotational speed NE, and the following equation (1) (step ST25).
P ₀ = k × (NI × NI−NE × NE) + k ₀ (1)
Note that k is a proportional constant and is a preset numerical value. Also, k ₀ is a constant, which is plus or minus one value.

  Here, the state of the hydraulic oil filled in each oil chamber in the torque converter 3 when the turbine impeller 3b and the front cover 3j rotate will be described. FIG. 7 is a diagram illustrating a hydraulic state in the torque converter. The hydraulic oil filled in each oil chamber of the torque converter 3 is affected by the rotation of the rotating body that comes into contact therewith. Accordingly, the hydraulic oil in the clutch engagement side oil chamber 3h is affected by the rotation of the contacting turbine impeller 3b, and the hydraulic oil in the clutch release side oil chamber 3i is affected by the rotation of the contacting front cover 3j. Further, the hydraulic oil filled in each oil chamber of the torque converter 3 is added with a centrifugal hydraulic pressure generated by the centrifugal force acting by the rotation of the rotating body in contact therewith. Accordingly, the centrifugal hydraulic pressure due to the rotation of the turbine impeller 3b is applied to the clutch engagement side oil chamber 3h, and the centrifugal hydraulic pressure due to the rotation of the front cover 3j is applied to the clutch release side oil chamber 3i.

When the rotating body in contact with the hydraulic oil in the torque converter 3 rotates, the centrifugal oil pressure applied to the hydraulic oil increases as it is positioned radially outward. Therefore, the clutch engagement side oil chamber and 3h radially inner oil chamber a is 3ha engagement side oil chamber side, the engagement side in径圧a hydraulic pressure of the engagement side oil chamber side 3ha P _3ha, clutch engaging When the engagement side oil chamber outer side which is the oil chamber on the radially outer side of the combined oil chamber 3h is 3hb, and the engagement side outer diameter pressure which is the hydraulic pressure of the engagement side oil chamber outer 3hb is _P3hb , the turbine impeller the centrifugal hydraulic pressure generated by the rotation of 3b, _{P 3hb} engagement side outer径圧is larger than the engaging side in径圧 _{P 3ha (P 3hb> P 3ha} ). Similarly, the release side oil chamber side that is a radially inner oil chamber of the clutch release side oil chamber 3i is defined as 3ia, and the release side inner pressure that is the hydraulic pressure inside the release side oil chamber side 3ia is _defined as P _3ia . Assuming that the oil chamber on the radially outer side of the release side oil chamber 3i is the release side oil chamber outer side 3ib, and the release side outer diameter pressure, which is the hydraulic pressure of the release side oil chamber outer side 3ib, is _P3ib , the centrifugal hydraulic pressure by the rotation of the front cover 3j. by, _{P 3Ib} release side outer径圧is larger than the release-side in径圧 _{P 3ia (P 3ib> P 3ia} ). The engagement side oil chamber outer side 3hb and the release side oil chamber outer side 3ib communicate with each other.

The engagement hydraulic pressure _{P 3h} is a hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber 3h is engagement side in径圧_{P 3ha} next _(P 3h ₌ P _3ha), is introduced into the clutch disengagement side oil chamber 3i The release side hydraulic pressure P _3i which is the hydraulic pressure of the hydraulic oil becomes the release side inner pressure P _3ia (P _3i = P _3ia ). When performing control by a control method according to the first embodiment shown in FIG. 7, by blocking the communication between the line pressure port 8m and hydraulic control oil chamber 8j is released, the release-side oil pressure and the engaging hydraulic pressure P _3h Since P _3i is equal (P _3h = P _3i ), the engagement-side inner pressure P _3ha and the release-side inner _pressure P _3ia are equal (P _3ha = P _3ia ). Further, since the hydraulic oil of the second line pressure Pl ₂ adjusted by the second pressure regulating valve 26 is introduced into the clutch engagement side oil chamber 3h, the engagement side inner pressure P _3ha and release side in径圧_{P 3iA} is equal to the second line pressure _{Pl 2 (P 3ha = P 3ia} = Pl 2) becomes. In other words, the release side in the engagement side in径圧_{P 3ha}径圧_{P 3iA} are equal _{(P 3ha = P 3ia = Pl} 2), and, if the turbine wheel 3b and the front cover 3j does not rotate, the clutch engagement side No centrifugal hydraulic pressure is generated in the oil chamber 3h and the clutch release side oil chamber 3i. Accordingly, the engagement-side outer径圧_{P 3hb} is equal to the engaging side in径圧_{P 3ha} becomes _{(P 3hb = P 3ha = Pl} 2), the release-side outer径圧_{P 3Ib} is equal to the release side in径圧_{P 3iA} Since (P _3ib = P _3ia = Pl ₂ ), the engagement-side outer _{diameter pressure} P _3hb and the disengagement-side outer _{diameter pressure} P _3ib are equal (P _3hb = P _3ib = Pl ₂ ).

The centrifugal oil pressure applied to the hydraulic oil in the torque converter 3 is proportional to the square of the rotational speed of the rotating body that comes into contact. Accordingly, the centrifugal hydraulic pressure in the clutch engagement side oil chamber 3h is proportional to the square of the output rotational speed NE, which is the rotational speed of the turbine impeller 3b, and the centrifugal hydraulic pressure in the clutch release side oil chamber 3i is the rotational speed of the front cover 3j. Is proportional to the square of the input rotational speed NI. Generally, the input rotational speed NI, which is the rotational speed of the front cover 3j, is higher than the output rotational speed NE, which is the rotational speed of the turbine impeller 3b, and therefore, between the input rotational speed NI and the output rotational speed NE. A rotational speed difference occurs. Therefore, due to the rotational speed difference generated between the input rotational speed NI and the output rotational speed NE, there is a difference between the centrifugal hydraulic pressure applied to the clutch engagement side oil chamber 3h and the centrifugal hydraulic pressure applied to the clutch release side oil chamber 3i. Will occur. In other words, when the engagement-side inner pressure P _3ha and the release-side inner _pressure P _3ia are equal (P _3ha = P _3ia ), and the turbine impeller 3b and the front cover 3j rotate to cause a rotational speed difference. A differential pressure due to the difference in centrifugal hydraulic pressure is generated between the clutch engagement side oil chamber 3h and the clutch release side oil chamber 3i having the same diameter as the clutch engagement side oil chamber 3h. The differential pressure due to the difference in centrifugal oil pressure increases as the diameter increases in the radial direction. Thus, the release-side outer径圧_{P 3Ib} is larger than the engaging side outer径圧 _{P 3hb (P 3ib> P 3hb} ) becomes, and the release-side outer径圧_{P 3Ib,} the engagement-side outer径圧_{P 3hb} The differential pressure between them becomes the maximum. Release-side outer径圧_{P 3Ib} is larger than the engaging side outer径圧_{P 3hb} becomes _{(P 3ib>} P _3hb), hydraulic oil to flow from the release side oil chamber outside 3Ib to engage side oil chamber outside 3hb The hydraulic oil in the circulation path that forms the closed circuit circulates. At this time, the clutch 3f is less likely to be engaged due to a differential pressure generated by the release side oil chamber outer side 3ib and the engagement side oil chamber outer side 3hb.

In the second embodiment, the value obtained by multiplying a value obtained by subtracting the square of the output rotational speed NE of the turbine impeller 3b from the square of the input rotational speed NI of the front cover 3j by the preset proportionality constant k (1 ) _{Is used} to calculate the control differential pressure P ₀ which is a value obtained by subtracting the engagement side hydraulic pressure P _3h from the release side hydraulic pressure P _3i , and the hydraulic control valve 8 is controlled based on the calculated control differential pressure P _0. . That is, by controlling the hydraulic control valve 8 based on the calculated control differential pressure P ₀ , the clutch disengagement side oil chamber 3i and the clutch engagement side oil are caused by the rotational speed difference between the front cover 3j and the turbine impeller 3b. The differential pressure generated between the chamber 3h and the chamber 3h can be reduced.

Next, as shown in FIG. 6, the transmission ECU 120 outputs a signal to the switching electromagnetic valve 5 so that the clutch switching valve 6 is turned on (step ST26). At this time, as shown in FIG. 5, the switching solenoid valve 5 that has received a signal from the transmission ECU 120 applies the switching signal pressure P _sw to the hydraulic pressure in the working pressure oil chamber 6 a of the clutch switching valve 6, thereby The switching valve 6 is turned on.

Next, transmission ECU120, based on the control differential pressure _{P 0,} and controls the hydraulic control valve 8 (step ST27). That is, the transmission ECU 120 outputs the drive current I _sol to the hydraulic control solenoid valve 7 so that the control differential pressure P ₀ calculated in step ST25 acts on the control signal pressure oil chamber 8l of the hydraulic control valve 8. Therefore, by adjusting to the control differential pressure P ₀ calculated by the expression (1) in step ST25, the circulation of the hydraulic oil in the circulation path due to the differential pressure can be suppressed to a small level. That is, by making it difficult for the hydraulic oil to circulate due to the differential pressure, it is possible to prevent the heat generated in the torque converter 3 from being discharged due to the hydraulic oil being discharged by the circulation. The temperature can be raised. Thereby, since lockup control can be performed at an early stage, the fuel consumption of the fluid transmission device can be improved. At this time, the control differential pressure P ₀ is set such that the clutch 3f is released. The hydraulic oil that has flowed into the second line pressure port 8n is in a state where the hydraulic pressure in the clutch disengagement side oil chamber 3i is controlled, so that the flow rate is adjusted by the fifth land 8i and discharged to the oil pan 21. When the transmission ECU 120 outputs a signal to the hydraulic control solenoid valve 7 so that the control signal pressure P _lin acting on the control signal pressure oil chamber 8 l of the hydraulic control valve 8 is output, the transmission ECU 120 shifts to the next control cycle.

In the second embodiment, the control differential pressure P ₀ is calculated based on the expression (1) as a method for calculating the control differential pressure P _0. However, the present invention is not limited to this. . For example, when the hydraulic oil temperature is low, control is performed to increase the control differential pressure P ₀ as the rotational speed difference increases. That is, it occurs between the clutch disengagement side oil chamber 3i and the clutch disengagement side oil chamber 3h having the same diameter as the clutch disengagement side oil chamber 3i as the rotational speed difference increases at the time of low oil temperature. with increasing differential pressure, increasing the control pressure difference P _0. That is, since the differential pressure generated between the release-side outer _diameter pressure P _3ib and the engagement-side outer _diameter pressure P _3hb can be reduced, the circulation of hydraulic oil in the circulation path can be suppressed. Thereby, the operating oil in the torque converter 3 can be efficiently heated.

In the second embodiment, the control differential pressure P ₀ is calculated based on the input rotation speed NI and the output rotation speed NE. However, the present invention is not limited to this. For example, when the hydraulic oil temperature is low, the pressure difference generated in the clutch disengagement side oil chamber 3i and the clutch engagement side oil chamber 3h is set to 0 or more in advance regardless of the input rotation speed NI and the output rotation speed NE. It performs control based on the control differential pressure P ₀ set. That is, since the differential pressure generated between the release-side outer _diameter pressure P _3ib and the engagement-side outer _diameter pressure P _3hb can be reduced, the circulation of hydraulic oil in the circulation path can be suppressed. Thereby, the operating oil in the torque converter 3 can be efficiently heated.

[Embodiment 3]
Next, the fluid transmission device 1 according to the third embodiment will be described. FIG. 8 is a diagram illustrating an example of the overall configuration of the fluid transmission device according to the third embodiment. FIG. 9 is a diagram illustrating a flow of the control method of the fluid transmission device according to the third embodiment. FIG. 10 is a diagram illustrating the hydraulic pressure in the torque converter of the fluid transmission device according to the third embodiment.

  The difference between the first embodiment and the third embodiment is that the control method of the hydraulic control valve 8 by the transmission ECU 120 is a blocking means for blocking the hydraulic oil circulation path in the first embodiment as shown in FIG. As shown in FIG. 9, the third embodiment is that a discharge cutoff valve 43 is used as a cutoff means for blocking the hydraulic oil circulation path. In the third embodiment, a spring 3k is provided in the torque converter 3 as a biasing means that biases the clutch 3f in a direction opposite to the direction in which the clutch 3f is engaged. The same basic components as those in the third embodiment and the first embodiment will be described below with omission or simplification.

  The discharge cutoff valve 43 is a cutoff means for blocking communication between the torque converter 3 and the discharge path 4. As shown in FIG. 8, the discharge cutoff valve 43 is provided in the middle of the discharge path 4, and is provided in a pipe between the oil cooler 41 and the hydraulic control valve 8. The exhaust cutoff valve 43 is connected to the transmission ECU 120. The discharge shut-off valve 43 is closed by a signal from the transmission ECU 120 when the clutch switching valve 6 is turned off when the hydraulic oil temperature is low. As a result, the discharge cutoff valve 43 blocks communication between the torque converter 3 and the discharge path 4.

  The spring 3k is a biasing unit that biases the clutch 3f in a direction opposite to the direction in which the clutch 3f is engaged. The spring 3k is provided in the clutch release side oil chamber 3i in the torque converter 3. In the third embodiment, the spring 3k is provided between the clutch 3f and the turbine impeller 3b. The biasing force generated by the spring 3k is a biasing force that suppresses the engagement of the clutch 3f that occurs when the discharge shutoff valve 43 is closed when the hydraulic oil is at a low oil temperature and the clutch switching valve 6 is off. is there. That is, the urging force generated by the spring 3k is smaller than the force acting in the direction in which the clutch 3f is engaged when the clutch switching valve 6 is on, as shown in FIG. Therefore, even if the fluid transmission device 1 has the spring 3k in the clutch release side oil chamber 3i, the clutch 3f can be engaged.

  Next, the control method of Embodiment 3 is demonstrated. Regarding the control method of the third embodiment, the same parts as those of the first embodiment will be described below with omission or simplification.

  As shown in FIG. 9, first, the transmission ECU 120 acquires the hydraulic oil temperature T received from the hydraulic oil temperature sensor 110 (step ST31).

  Next, the transmission ECU 120 determines whether or not the oil temperature T of the hydraulic oil is equal to or lower than the specified oil temperature T1 (step ST32). Thereby, it is determined whether the hydraulic oil circulating in the torque converter 3 has a low oil temperature.

  Next, when the transmission ECU 120 determines that the hydraulic oil temperature T is equal to or lower than the specified oil temperature T1 (Yes in step ST32), the transmission ECU 120 outputs a lockup prohibition flag (step ST33). In addition, transmission ECU120 will output a lockup permission flag, if it judges that the oil temperature T of the received hydraulic fluid is not below regulation oil temperature T1 (step ST32 negative) (step ST36). As a result, lock-up is permitted and the process proceeds to the next control cycle.

Next, the transmission ECU 120 outputs a signal to the switching electromagnetic valve 5 so that the clutch switching valve 6 is turned off (step ST34). At this time, as shown in FIG. 8, since the clutch switching valve 6 is in the off state and the drive current I _sol is not output to the hydraulic control solenoid valve 7, the hydraulic oil is circulated in step ST34. In the path, the hydraulic oil supplied from the supply path 2 is introduced into the clutch disengagement side oil chamber 3i of the torque converter 3, and the hydraulic oil flowing into the clutch engagement side oil chamber 3h is discharged to the discharge path 4. It becomes a route.

  Next, as shown in FIG. 9, the transmission ECU 120 outputs a valve closing signal to the discharge cutoff valve 43 (step ST35). When the valve closing signal is received from the transmission ECU 120, the discharge cutoff valve 43 is closed to cut off the hydraulic oil flowing out from the hydraulic control valve 8 to the discharge path 4. That is, the hydraulic oil circulation path can be blocked by the discharge cutoff valve 43. Therefore, by closing the discharge cutoff valve 43 when the clutch switching valve 6 is off when the hydraulic oil temperature is low, the hydraulic oil circulation path when the clutch switching valve 6 is off can be forcibly cut off. . Since the discharge shut-off valve 43 is provided in the pipe between the oil cooler 41 and the hydraulic control valve 8, contact between the hydraulic oil and the oil cooler 41 can be avoided. Thereby, since it can suppress that the heat | fever which generate | occur | produces in the torque converter 3 by contact with hydraulic fluid and the oil cooler 41 can be suppressed, it can raise the temperature of hydraulic fluid in the torque converter 3 efficiently. it can. When the transmission ECU 120 outputs a valve closing signal to the discharge cutoff valve 43, the transmission ECU 120 shifts to the next control cycle.

Here, the hydraulic pressure of the hydraulic oil filled in the torque converter 3 according to the third embodiment will be described. As shown in FIG. 10, since the clutch switching valve 6 is in the off state, the second line pressure Pl ₂ is introduced into the release-side oil chamber side 3ia via the release-side port 6h of the clutch switching valve 6. (P _3ib = Pl ₂ ). _Further , the magnitude relationship between the release-side inner pressure P _3ia and the release-side outer pressure P _3ib is P _3ib > P _3ia due to the centrifugal hydraulic pressure when the turbine impeller 3b and the front cover 3j rotate. Further, when the discharge shut-off valve 43 is closed, the circulation path is forcibly cut off, a closed circuit for the working oil is formed, and the circulation of the working oil in the torque converter 3 is stopped. Therefore, when the circulation of the hydraulic oil in the torque converter 3 is stopped, the engagement side outer diameter pressure P _3hb which is the hydraulic pressure of the engagement side oil chamber outer side _3hb and the engagement side oil chamber outer side 3hb are communicated. The release side outer diameter pressure P _3ib which is the hydraulic pressure of the release side oil chamber outer side _3ib becomes the same pressure. Thereby, since the inflow of the hydraulic oil from the release side oil chamber outer side 3ib to the engagement side oil chamber outer side 3hb can be suppressed, the temperature of the hydraulic oil in the torque converter 3 can be efficiently increased. Thereby, the lockup control can be performed at an early stage, so that the fuel consumption of the fluid transmission device 1 can be improved.

Similar to the clutch disengagement side oil chamber 3i, the even clutch engagement side oil chamber 3h, the centrifugal hydraulic pressure, the magnitude relationship between the engagement side in径圧_{P 3ha} engaging side outer径圧_{P 3hb is, P 3hb} > P _3ha . Further, when the turbine impeller 3b and the front cover 3j rotate to cause a rotational speed difference, a differential pressure due to a difference in centrifugal oil pressure between the clutch engagement side oil chamber 3h and the clutch release side oil chamber 3i. Occurs. Therefore, when the circulation path is shut off by the discharge shut-off valve 43, a differential pressure is generated between the clutch engagement side oil chamber 3h and the clutch release side oil chamber 3i due to the difference in the rotation speed, so that the engagement side inner径圧_{P 3ha} is greater than the release-side in径圧 _{P 3ia (P 3ha> P 3ia} ).

  In the fluid transmission device 1 according to the third embodiment, the spring 3k that biases the clutch 3f in the direction opposite to the direction in which the clutch 3f is applied is applied to the clutch release side with respect to the force applied in the direction in which the clutch 3f is engaged. It is provided in the oil chamber 3i. That is, when the hydraulic oil is at a low oil temperature and the clutch switching valve 6 is turned off and the discharge shut-off valve 43 is closed, there is a gap between the clutch engagement side oil chamber 3h and the clutch release side oil chamber 3i. A clutch 3f may be engaged by applying a force to the clutch 3f in a direction to engage with the front cover 3j due to a differential pressure due to a difference in generated centrifugal hydraulic pressure. At this time, the urging force of the spring 3k urges the clutch 3f in the direction opposite to the direction in which the clutch 3f is engaged, thereby suppressing the engagement of the clutch 3f that occurs when the discharge cutoff valve 43 is closed. be able to.

  As described above, the fluid transmission device according to the present invention is useful in that the temperature of the hydraulic oil can be efficiently raised when the hydraulic oil is at a low oil temperature.

It is a figure which shows the example of whole structure of the fluid transmission apparatus concerning Embodiment 1 (at the time of clutch release). It is a figure which shows the example of whole structure of the fluid transmission apparatus concerning Embodiment 1 (at the time of clutch engagement). FIG. 3 is a diagram illustrating a flow of a control method of the fluid transmission device according to the first exemplary embodiment. It is a figure which shows the example of whole structure of the fluid transmission apparatus concerning Embodiment 1. FIG. It is a figure which shows the example of whole structure of the fluid transmission apparatus concerning Embodiment 2. FIG. FIG. 6 is a diagram illustrating a flow of a control method of the fluid transmission device according to the second exemplary embodiment. It is a figure which shows the hydraulic state in a torque converter. It is a figure which shows the example of whole structure of the fluid transmission apparatus concerning Embodiment 3. FIG. FIG. 10 is a diagram illustrating a flow of a control method of the fluid transmission device according to the third exemplary embodiment. FIG. 6 is a diagram showing a hydraulic state in a torque converter according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluid transmission apparatus 2 Supply path 22 Pressurization pump 26 2nd pressure regulation valve 3 Torque converter 3a Pump impeller 3b Turbine impeller 3f Clutch 3h Clutch engagement side oil chamber 3i Clutch release side oil chamber 3j Front cover 3k Spring 4 Discharge path 41 oil cooler 43 discharge shut-off valve 5 switching solenoid valve 6 clutch switching valve 6a working pressure oil chamber 6b spool valve element 6i counteracting pressure oil chamber 7 hydraulic control solenoid valve 7a control solenoid solenoid 7b spool valve element 7f solenoid oil chamber 8 Hydraulic control valve 8a Communication side oil chamber 8b Hydraulic control side oil chamber 8c Plunger 8d 1st land 8e 2nd land 8f Spool valve 8g 3rd land 8h 4th land 8i 5th land 8j Hydraulic control oil chamber 8l Control signal pressure Oil chamber 8m Line pressure port 8n Second line pressure port 101 Crank 102径圧transmission shaft 110 working oil temperature sensor 111 input shaft speed sensor 112 output shaft speed sensor P _3ha engagement side in径圧P _3iA release side in P _3hb engaging side outer径圧P _3Ib release side outer径圧OCS hydraulic Control device

Claims (8)

It has a fluid transmission mechanism that transmits the driving force generated by the drive source using hydraulic oil as a medium, and is based on the differential pressure between the clutch engagement side oil chamber and the clutch release side oil chamber partitioned by the clutch in the fluid transmission mechanism. In the fluid transmission device that transmits the driving force without involving the hydraulic oil by engaging the clutch,
A discharge path for discharging the hydraulic oil supplied to the fluid transmission mechanism;
A supply path for pressurizing the hydraulic oil discharged from the discharge path and supplying the hydraulic oil to the fluid transmission mechanism;
The supply path and the clutch engagement side oil chamber communicate with each other to engage the clutch by supplying the hydraulic oil to the clutch engagement side oil chamber, or the supply path and the clutch release side A hydraulic control device for releasing engagement of the clutch by communicating with an oil chamber and supplying the hydraulic oil to the clutch release side oil chamber;
A blocking means for blocking communication between the fluid transmission mechanism and the discharge path at a low oil temperature of the hydraulic oil;
A fluid transmission device comprising: The hydraulic control device includes:
a clutch switching valve that communicates the fluid transmission mechanism and the discharge path when off, and shuts off the communication between the fluid transmission mechanism and the discharge path when on;
A hydraulic control valve that controls the hydraulic pressure of the hydraulic oil introduced into the clutch disengagement side oil chamber with respect to the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber when the clutch switching valve is on;
With
The clutch switching valve is a shut-off means,
The fluid transmission device according to claim 1, wherein the clutch switching valve is turned on when the hydraulic oil has a low oil temperature. The hydraulic control valve is a value obtained by subtracting the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber from the hydraulic pressure of the hydraulic oil introduced into the clutch release side oil chamber when the hydraulic oil is at a low oil temperature. The fluid transmission device according to claim 2, wherein the control differential pressure P _{0 is set} to 0 or more when a certain control differential pressure is P ₀ . The fluid transmission mechanism includes a torque converter comprising: an input-side rotator that transmits a driving force; and an output-side rotator that transmits a driving force transmitted to the input-side rotator via the hydraulic oil. Fluid coupling,
The hydraulic control valve is configured to increase the control differential pressure in accordance with an increase in a rotational speed difference that is a value obtained by subtracting the rotational speed of the output-side rotating body from the rotational speed of the input-side rotating body at a low oil temperature of the hydraulic oil. The fluid transmission device according to claim 3, wherein P ₀ is increased and controlled. An input rotation speed is the rotation speed of the input side rotating body NI, the output rotational speed is the rotational speed of the output rotary member NE, the proportionality constant k and the constant when the K _0,
The fluid transmission device according to claim 4, wherein the hydraulic control valve controls the control differential pressure P ₀ based on the following equation (1).
P ₀ = k × (NI × NI−NE × NE) + K ₀ (1) The fluid transmission device according to claim 2, wherein the hydraulic control valve sets the control differential pressure P ₀ to zero. The hydraulic control device includes:
a clutch switching valve that communicates the fluid transmission mechanism and the discharge path when off, and shuts off the communication between the fluid transmission mechanism and the discharge path when on;
A hydraulic control valve that controls the hydraulic pressure of the hydraulic oil introduced into the clutch disengagement side oil chamber with respect to the hydraulic pressure of the hydraulic oil introduced into the clutch engagement side oil chamber when the clutch switching valve is on;
With
The blocking means is a discharge blocking valve that blocks communication between the fluid transmission mechanism and the discharge path;
The fluid transmission mechanism is provided with a biasing means for biasing the clutch in a direction opposite to a direction in which the clutch is engaged,
3. The fluid transmission device according to claim 2, wherein when the hydraulic oil temperature is low, the clutch switching valve is turned off, and communication between the fluid transmission mechanism and the discharge path is blocked by the discharge cutoff valve. The hydraulic control device engages the clutch by communicating the supply path and the clutch engagement side oil chamber when on, and communicates the supply path and the clutch release side oil chamber when off. A clutch switching valve for releasing the engagement of the clutch;
The blocking means is a discharge blocking valve that blocks communication between the fluid transmission mechanism and the discharge path;
The fluid transmission mechanism further includes a biasing unit that biases the clutch in a direction opposite to a direction in which the clutch is engaged.
The fluid transmission device according to claim 1, wherein communication between the fluid transmission mechanism and the discharge path is blocked by the discharge cutoff valve when the temperature of the hydraulic oil is low.

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